Candida diseases are often chronic, difficult to treat, and carry a high mortality and morbidity despite anti-fungal therapy. Candida spp. are the third leading cause of infections in ICUs globally, accounting for up to 90% of all fungal infections.
The diagnosis of invasive candidiasis is difficult due to the lack of specific clinical features and to the low sensitivity of blood culture for isolation of Candida species, especially in patients receiving fluconazole prophylaxis. A positive blood culture for Candida spp. remains the gold standard for the diagnosis of candidemia. However, Candida spp. isolation may take too much time, thereby delaying effective antifungal therapy. Candida albicans is the most important human fungal pathogen. Particularly, Candida albicans (C. albicans) is an opportunistic human pathogen, which colonizes at several sites including skin, oral tissue, gastrointestinal track and vagina. C. albicans is also a major pathogen responsible for 50.4% of clinical candidemia. Candidemia can occur when Candida yeasts enter the bloodstream and is rarely seen in healthy people. In recent decades, due to the increase of patient population with defective immunological functions, Candidemia has become an important issue. Amphotericin (AmB) is a gold standard of antifungal treatment for fungi, but the severe side effect of this drug restricts its clinical application. Widespread and prolonged use of azoles has led to the rapid development of multidrug resistance (MDR), which poses a major hurdle in antifungal therapy. Several reports show that the incidence of resistance to fluconazole has risen during the last two decades.
Enolase is present in all tissues and organisms capable of glycolysis or fermentation. ENO1 was first identified as a key component of the glycolytic pathway. ENO1 is ubiquitously expressed in the cytosol and also found on the cell surface as a plaminogen-binding receptor. Candida albicans ENO1 null mutants exhibit altered drug susceptibility, hyphal formation, and virulence. The expression of ENO1 in the fungal pathogen Candida albicans is critical for cell growth. Mutations on ENO1 in Candida albicans inhibit cell growth in the presence of glucose. ScFv is a recombinant antibody protein, which consists of the variable regions of heavy chain (VH) and light chain (VL), combining by a linker peptide. In a previous study, anti-CaENO1 scFv antibody (CaS1) was isolated by phage display, but the interaction (epitope) of CaENO1 with CaS1 is not clear. There is a need to explore and develop a target regarding CaS1 scFv inhibition against the interaction between CaENO1 and plasminogen.